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3 years ago

Why are plastic building blocks good for building molecules

Chemistry

2 answers:

Nina [5.8K]3 years ago

8 0

Because they're durable and can provide a somewhat accurate visual representation.

9966 [12]3 years ago

5 0

Plastic building blocks are good for building molecules because of some useful properties which they possess. For instance, plastic are flexible, they can be easily manipulated and can be made into any shape, size and combination. They can also be produced using different colors. Because of these features, they can be used to build and to explain how molecules behave.

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The most familiar elements are typically the most

rodikova [14]

-Are the most used in daily life and basic human needs

(such as oxygen,nitrogen,carbon, etc)

4 0

3 years ago

Read 2 more answers

A sample of seawater contains 1.3g of calcium ions in 3,100kg of solution. what is the calcium ion concentration of this solutio

MakcuM [25]

Unit ppm stands for parts per million. in terms of mass, ppm is equivalent to mg/kg.
since 1 kg is 10⁻⁶ mg, 1 kg is equivalent to million mg.
therefore mg/kg is also ppm.
there are 1.3 g of Ca ions in 3100 kg
if 3100 kg contains - 1.3 g of Ca
then 1 kg contains - 1.3 g / 3100 kg
then Ca ions - 0.42 x 10⁻³ g/kg
Ca ion concentration - 0.42 mg/kg
therefore Ca ion concentration is 0.42 ppm

8 0

3 years ago

Hydrogen can be extracted from natural gas according to the following reaction:

evablogger [386]

Answer:

There will be produced 379 grams of H2

The percent yield under these conditions is 7.45 %

Explanation:

Step 1: The balanced equation

CH4(g)+CO2(g) → 2CO(g)+2H2(g)

Step 2: Given data

Kp = 4.5*10²

Temperature = 825 Kelvin

Volume = 85.0 L

Mass of CH4 = 22.3 Kg

Mass of CO2 = 55.4 Kg

Molar mass of CH4 = 16.04 g/mole

Molar mass of CO2 = 44.01 g/mole

Step 3: Calculate moles of CH4

moles of CH4 = mass of CH4 / Molar mass of CH4

moles of CH4 = 22300 / 16.04 = 1390.3

Step 4: Calculate moles of CO2

moles of CO2 = mass of CO2 / Molar mass of CO2

moles of CO2 = 55400 / 44.01 = 1258.80 moles

Step 5: Calculate moles of H2

For 1 mole of CH4 we need 1 mole of CO2 to produce 2 moles of H2

so there will be produced 2*1258.8 = 2517.6 moles of H2

Step 6: Calculate theoretical mass of H2

mass of H2 = Number of moles of H2 * Molar mass of H2

mass of H2 = 2517.6 moles *2.02 g/mole = 5085.552 grams

Step 7: Calculate pressure of CH4

P*V = n*R*T

P =(n*R*T) / V

P = 1390.3*.0821*825/85 = 1107.86atm

Step 8: Calculate pressure of CO2

P*V = n*R*T

P =(n*R*T) / V

P = 1258.80*.0821*825/85 = 1003.08atm

Step 9

Kp= 4.5 *100 =[P(H2)^2 * P(CO)^2]/[P(CO2) * P(CH4)]

450=16X^4/[(1107.86-X)(1003.08-X)]

450=16X^4/[(1107.86)(1003.08)]

(1107.86)(1003.08)*450=16X^4

X = 74.77

We plug this value in for "X" in the ICE chart. Only H2 since thats what the problem wants.

for H2 (2 moles) so 2X = 2*74.77 = 149.54

Step 10: Calculate number of moles of H2

n = P*V/ R*T

n = (149.54 *85 )/(0.0821 * 825) = 187.66 moles H2

Step 11: Calculate mass of H2

mass of H2 = Number of moles H2 * Molar mass of H2

mass of H2 = 187.66 * 2.02 g/moles = 379.07 grams H2 ≈ 379 grams of H2

Step 12: Calculate the yield

(379 grams of H2 / 5085.552 grams of H2 ) * 100 % = 7.45 %

The percent yield under these conditions is 7.45 %

3 0

3 years ago

I need help with my science homework and it’s hard like this exp The orbit of the planets in our solar system is generally due t

yaroslaw [1]

The solar system is made up of the sun and everything that orbits around it, including planets, moons, asteroids, comets and meteoroids. It extends from the sun, called Sol by the ancient Romans, and goes past the four inner planets, through the Asteroid Belt to the four gas giants and on to the disk-shaped Kuiper Belt and far beyond to the teardrop-shaped heliopause. Scientists estimate that the edge of the solar system is about 9 billion miles (15 billion kilometers) from the sun. Beyond the heliopause lies the giant, spherical Oort Cloud, which is thought to surround the solar system.

5 0

3 years ago

Compare catalytic and thermal cracking

meriva

Answer:

Catalytic cracking is an important process in the oil industry where petroleum vapor passes through a low-density bed of catalyst, which causes the heavier fractions to 'crack' producing lighter more valuable products

Thermal cracking is an extraction process in which hydrocarbons such as crude oil are heated to a high temperature to break the molecular bonds. Thermal cracking is a refining process in which heat and pressure are used to break down, rearrange, or combine hydrocarbon molecules.

Explanation:

7 0

3 years ago